The invention discloses a method and device for monitoring the client side signal feature. The method includes the steps that a client side address in a database is acquired, and after a detection message is sent to the client side address, the signal feature generated when a client side responds to the message is monitored, wherein the detection message is the message to which the client side can respond after the client side receives the message. By the adoption of the technical scheme, through the mode that the detection message is actively sent to the client side, and the client side sends a response message and effectively receives the response message, the probability that the message sent by the client side is captured is increased, the monitoring reliability of the client side signal feature is improved, and good use of value-added services is guaranteed.